The DE69220550T3 discloses a manufacturing method for a sewing machine needle with a reduced scarf width. The width of the scarf is particularly smaller than the height of the scarf. The intention is for the needle to encounter less penetration resistance.
EP1052324A2 discloses a flat scarf that is rounded to avoid sharp edges of the scarf damaging the fabrics to be sewn. Thus, the cross-sectional contour of the scarf nearby the center portion of the scarf is not rounded at all or at least has a very big radius of curvature. Near to the edges of the scarf the radius is very small. As a consequence there are broad side faces parallel to a line 9 in the direction as the eye of the needle.
U.S. Pat. No. 3,589,428A discloses a method for the manufacture of a sewing machine needle forming a flat section in advance of forming a longitudinal groove. The sewing machine needle has no scarf.
DE3027534A1 discloses a sewing machine needle with a scarf displaced parallel to the rest of the blade. The displaced scarf offers enlarged space between the thread and the needle. Thus, picking of the loop is facilitated for the looper. The displacement of the blade, especially the descent to the shifted section can cause damages to the fabrics to be sewn when retracting the needle. The cross-sectional surface area of the needle in the section of the scarf is the same or only slightly smaller than the cross-sectional surface area of the blade apart from the scarf. Similar solutions with the same differences to the actual invention are disclosed in U.S. Pat. No. 4,458,614A and EP1052323A2.